If you are using software, such as ProScan, there's not a lot of difference about "how hard" either of those scanners is to program them.
For the 996P2, you would have to program
everything you wanted to listen to,
For the 536HP (the HP suffix does indicate it;s a scanner in the Home Patrol series), you can simply update the main database, then scan using your
location & a range, plus specifying the types of things you want to monitor. That's good if you are taking a road trip. Make sure the database is up to date, connect a GPS to the scanner & hit the road. The GPS will enable systems in range as you drive, turning off those that are passing out of range. However, you probably would find that, long term, you'd be happier using a Favorites list for the agencies in your area that interest you.
The basis of the programming between the two scanners is not that different. In the 996P2, you have Systems, (sites for trunked systems), and groups, which are a collection of channels (conventional channel frequencies, or talkgroups in a trunked system). For the 536HP, or any of the scanners that fall under the 'Home Patrol' classification, you have systems, sites, and Departments. The 'Department' of any of the HP scanners is the same as what is called a 'group' in the 996P2 & other DMA scanners.
The biggest difference is that in the HP type scanners, you can collect systems (and their components) and program them into a Favorites list. You can have a number of them created & stored on their memory card, and select which ones you want to monitor at any one time. For the 996P2, you can program a number of systems, and select which specific ones you want to hear, as long as you programmed them in advance. The 536HP has a display with more information than the 996P2. Plus, the 536HP, and other Home Patrol scanners, can record what it's hearing on it's memory card, even when not connected to your PC. For the 996P2, the only way you can record anything is if it's connected to a computer's sound card. Cost wise, the 996P2 is currently a little over $350 on Amazon, and the 536HP is $489. ScannerMaster is about $40 higher on each. Of course, ScannerMaster & other dealers such as Bearcat Warehouse, can give you more technical support, answering questions,. But if you know what you want, and don't need any hand-holding from your dealer, I'd order from Amazon. Amazon has a very flexible return policy, no restock fees, and if you have a Prime membership, they pay the return shipping as well. Many of the dealers do charge a restock fee for returns, plus you are paying the shipping for returns, and in most cases for it to be shipped to you. At the price points for these scanners, Amazon shipping to you is at no charge.
Regardless of what you buy, and where your purchase is made,
do not pay a dealer to program a scanner. There's practically endless threads here on the forums about programming, plus Wiki pages, as well as dozens of 'how to videos' on YouTube. You might find someone in your state who can share a programming file more specific to your area. For the 996P2, you will need software; while you can program through the keypad, it can be very tedious and time consuming, especially when it comes to text tags. Looking at your county, I do not see any current listings for agencies using DMR or NXDN, though some of the school districts in surrounding counties are using DMR (those might not be of interest). Since you are a Premium Subscriber, you could use FreeSCAN to aid in importing what you want to hear (as long as none of the systems that interest you use DMR or NXDN). However, that software is no longer supported,
ProScan is a much better choice, The 536HP does need Sentinel (free from Uniden) to maintain the database, and it can handle programming (though not imports). ProScan can be used on either the 996P2 or the 536HP, as well as a large number of other Uniden scanners. Should you, at some point, find that you have some DMR or NXDN systems of interest, either of these scanners can accept the paid upgrades for those two modes. Don't pay a dealer to do that for you, You can register the scanner on Uniden's site, & purchase the upgrades at a cost of $15 to $25 (or even more) less than what the dealer would charge you.