the winsor block is the better bet for high horsepower, it can be built to over 450 cui, and the svo blocks are safe over 1500 hp. just ask any 5.0 racer.. the 302 is hard to beat.. and if you are budget minded, tubular stainless TT headers for the winsor retail for 300 bucks on ebay..
In my oppinion the best bet is to stick with a 302 and do a clean and well engineered turbosetup.. and if you dont like the ford distributor then instal direct fire ignition.. it is not the engine model that impress me its the craftsmanship in the install.. look at a nelson TT sbc.. its a smallblock chevy, like 60 million others, but im hard pressed to find an engine id rather have..
4.6 dohc is approx 650 pounds which is the nearly the same as a Big Block Chevy. You can save a few hundred pounds off the front end using a windsor. The 4.6 has more bling but any thing other than a ls motor with twins has a lot of bling.
In my opinion mod motors are worthless. They weigh as much as a big block and its hard (and expensive) to get a 4 valve motor. The problem with a 302 is the block will split at about 475 horsepower. Now if you are willing to go with an aftermarket block (like fords new boss block) you are in business. If you are looking to keep a stock block I would go with a 351, they can take 700 horsepower. The front oil pump problem can be resolved by using a latemodel rearsump oil pan. BTW a windsor will be a lot cheaper to build. If you really want to make some power look into AFR, Canfield, or RHS heads.