As you have heard mods for a 4.6 is still quite costly.(look at mine )....but the prices are falling. The prices are getting closer to the cost of 5.0 mods and with the future of the ohc engine and the number of sales prices will continue to drop
The 4.6 is fun to drive and makes alot of power without cam work.As you can see I opted for a new engine instead of just a head & intake upgrade,parts for these cars found at salvage yards are starting to pop-up
Alot of companies have also made alot of body and interior kits for this model also. So I'd say get a good inspection and history of YOUR car and let the fun begin.
P.S. The 96 is rated at about 215 hp(comparable to the 94-95 5.0)