Howell was easy to install if you just take it step by step and follow the instructions. It took me a total of about 5 hours. Not hard at all, I was surprised, I was ready for all of the FI install horror stories, but Howell's wiring harness (the hardest part if you did it yourself) made it easy.
Well worth the money - I paid $1100 US direct from Howell (with the heated O2 sensor).

I would not recommend trying to piece it together yourself.