I haven't used the MFJ-901B but it looks reasonable. Read reviews here https://www.eham.net/reviews/detail/678 on eham. That said, you might peruse hamfests or club estate sales for used tuners. Short of lightening damage or exceeding power levels, an older unit should suffice. I had two DenTron DenTron Super Tuners capable of handling even a 10-foot wire on 160m. It looks like you are on the right path. Don't overcomplicate your life. As you commented before, KISS works. Plug 3.5 MHz into this Antenna Length Calculator KD4SAI calculator and you'll see why I suggested a 135 feet wire. Go to it. Good luck.