You know, what got me started was the need for a good (read louder and melodic) exhaust system. From there you may find the dominoe effect take over!
Muzzy will give you a map for that M14 exhaust, even if you don't buy direct from them. The map I got from Muzzy was the best I had until I got a custom map. (Another option, FAICS custom maps) There is an advantage to buying the Power Commander from an outfit like FuelMoto because they have an assortment of maps available. Although they don't have the best track record for response time. The DynoJet company offers a pathetic few maps for their Power Commander. Tuning on a Dyno machine ($200+) is costly and you should wait until all your mods are in place to have it done*. The ZX14 has an altitude sensor to automatically adjust for thinner air so doing a Dyno for that alone is not necessary.
You can get OK deals on E-bay for a lot of "things." But not like the old days when good deals were the norm. It now seems to be a place for people to try to get rich! I've seen stuff on E-Bay offered for more than many retailers sell for! You can also check the For Sale sections of the many motorcycle forums. Some killer deals there.
I would agree with riding stock gearing for a while. The 14 will seem Uber fast no matter what your old ride was. You'll enjoy just trying to hang on running stock. But eventually, if you're like most of us, you'll want a little more pick up.
*I'm on month 9 of adding mods and might never be done. It's kind of addictive. It's kinda like owning a boat. You know, a hole in the water into which you pour money you don't need.
008 ZX14R Ninja ... Midnight saphire blue with custom lightning bolt paint job, Kenny Rodgers KRTuned mufflers, Corbin custom seat, Marchesini wheels, Dunlop Qualifiers, Dyno Jet PCIII, custom FAICS map, Dyno Jet Ignition Module, K&N Air Filter, Supersprox 44 tooth sprocket, Zephyr 16 front sprocket, EK chain, TRE008, MRA windscreen, Race Railz frame sliders, Sato Racing axle sliders, ST Machine brake & clutch levers, Engine Ice coolant, Muzzy aluminum fan, ceramic coated headers and midpipes (cat removed), Vortex Rear Sets , Pro Comp Stearing Damper, Pro Grip Gel handgrips, Gen Mar clip on risers, Dowco tank bag, and a Rumble fender eliminator.
Removed GPS.
2005 Harley Davidson Dyna Low Rider, 1442 CI fuel injected, 65 HP, lots of chrome with 24K gold overlay detailing. Sure is pretty!