After tearing my whole car apart to purge the oil coolers (M209 filter had internal failure, resulting in contamination), I am lusting for more driving and more hp :P I'll be taking it easy for the next 1,000 miles until I change all my oil and filter again and ensure there is no more crap in my lines

. I know Lotus recommends replacing both coolers, but I did a freakishly thorough job, detailed in the maintenance section...
Anyway,
If I want to change the pulley I would have to purchase a standalone EFI system I take it. My goal is to get the car to dyno at around 275-300 whp. It doesn't sound like that's going to happen without an investment cost of at least 1.5K or so.
I guess I need a place to start, I don't want to spend all the money at once.
1. What's a good first move toward these mods?
It seems like a stand alone EFI would allow me to play with my tuning and increase my hp a little.
2. Can I tune it myself without a dyno (Is there a way to get feedback such as torque curves)? Is there a way to go back to default settings when I make it so my car won't run by accident?
3. I'm a n00b and need some clarification. EFI = fuel injection, only? How does a stand alone EFI system relate to the ECU. Will I need to reprogram my ECU with a separate interface?
Feel free to point me to other threads, I have browsed, but haven't been able to figure out a logical progression for the modifications I am considering. So, thanks a bunch for the advice, I'm looking forward to learning all this stuff. The most useful response would be one that lays out a sequence of modifications that are additive and result in around 300 Whp when all are finished.