Nothing against ScannerMaster, but you can order the MCA204M with an N input for $195 directly from Stridsberg: Receiver Multicouplers, Passive and Active, HF to VHF/UHF
and save yourself the trouble (and small signal loss) of buying and using one additional adapter.
I agree with the other poster. If you've got money for a pre-amp, you'll likely be better off spending it on a filter instead. Of course, you know your own listening environment best. You could wait, and purchase a pre-amp later if you find you're not getting enough signal from your new setup.
Stridsberg also sells BNC jumpers which are quite nice and work very well, but are somewhat expensive. Their cables are very flexible and won't put stress on your scanner's antenna connector. Another good source of BNC jumpers is the used test equipment market. You can often find quality BNC jumpers that are flexible with premium connectors for a good price at places selling used test equipment.
I love late winter and early spring. It means antenna season is just around the corner! Obviously, be careful erecting your new antenna. Think about grounding the cable and mast appropriately. But, most of all, have fun.