OK.

Let's assume somone's going to go the mod route and tune. My understanding is there's a need for logger, something to analyze it all with (PC/laptop), a wideband sensor (???).

What are the cost-effective suggestions and other items required after tach and boost gauge?

Thanks!

best tuning tools with a stock ECU:
boost guage
OBDII logger
adjustable FPR(very nice with larger than stock injectors)
wideband O2(I put this last, you'll see knock with the logger)

www.pocketlogger.com

Check here for PDA compatibility with their software. They supply the software and the cable. Best thing I've bought for my DSM.

(JMoushon) <--- I would think that if you want to make the necessary adjustments after logging, you would also need something to adjust fuel, like the AFC or MAF-T. Knowing where you are is great, but being able to optimize is far better.