If you want a pd I'd go with a dob manifold and 2.9 Whipple. The whipple can feed your 326 and keep iats down.
A Paxton is the most economical blower. A 1200SL or 2200SL both have the same 1150cfm blower (same as a V3 Vortech). It's limited to 52,000 rpm so keep that in mind. You will have to upgrade to a better blower to have more potential. The YSI series will give you plenty of room to grow.
A Procharger D1 has a 62,000 rpm limit, billet wheel, and moves 1400 cfm. It has about the same potential as the 2000 series Paxton with a higher rpm limit (Edit: I had originally grouped the YSI in with the 2000 series but they are not the same. The YSI is a 1600 cfm blower with a 65,000 rpm limit) but comes with it's own 8 rib drive belt and tensioner. The kit is also already configured as a blow through too. There are several D1 kits in the classifieds for good prices.
A big advantage to a centri with a higher rpm rating is obviously the ability for more boost but also for more boost faster. The D1 has a 4.1 drive ratio vs 3.6 for a 1200 series Paxton. The steeper the drive ratio the faster boost builds. It's possible to configure a centri so that power comes on almost as fast as a pd but with a little more linearity. You can also install a wastegate to control boost while maintaining the fast boost buildup.
19cobra93 had a rotrex for sale, not sure if he still does. It's a nice centri with a 5.7 drive ratio which really builds the boost fast.
You have the right idea, figure out what you really want and only spend the money once. Buy good parts and do it right. You are limiting yourself by only considering something Brenspeed sells or will tune.