Congratulations to start with.
A good post and honest about the process and difficulties.
All though I can't comment on the conversion as I did a JAA IR first I lived with 4 other gents in a B&B who had to do "20 hours conversion" and the majority were up around 40-50 hours. A couple were even taking longer than the full course due to primacy. (I.e what you learn first sticks and it is much harder to adjust than learn from scratch properly the first time)
If I were to recommend the FAA IR - the only way I consider it to be worth while is all of the course in the multi.
Doing all FAA training then converting is definitely not more economical - I have yet to meet someone who saved money from 0 to JAA. A half way house is to complete JAA training in the USA which is cheaper than JAA in the UK at least.
And last but not least :
Nothing in the US will every prepare you adequately for the JAA IR compared to the FAA IR.
A local FAA DPE where I did my FAA conversions had UK JAA licences/ratings as well. He said the FAA IR was more like a UK IMC and the JAA IR was similar to the FAA ATP.