id advise looking through peoples build threads and the turbo and power thread http://www.sau.com.au/forums/topic/55845-rb25-turbo-upgrade-all-dyno-results/page-1you'll soon see what's reliable and what turbo makes what power with other modifications. May seem like a bit of work, but that's half the fun and it will broaden your ideas and open new possibilities.
Changing plugs isn't that much of an inconvenience with the standard plenum and J pipe. Should only take a few minutes, like 5-10 tops.
FFP do look nice if they are rippled like standard, i have never used one or seen a back to back test vs standard so i can't comment on their 'power'.
Take a good look at the engine bay and you'll soon realise that the wiring loom, vac hoses, and power steering reservoir etc are the things that 'clutter' the engine bay. Personally, i'd start with a wire tuck and moving reservoirs if you're into cleaning it up a bit. It will be cheaper and keep you 'tinkering' for longer. Ever seen a 25 wire tucked and cleaned? looks a shitload better than a cluttered bay with a ftp.