Hi Ste I did the same as you at the ripe old age of 51 best thing I ever did,
I to was thinking peg XL but my instructor put me off telling me they are a fine a/c but very slow, and the days you fly have to be very carefully chosen,
He advised me to go for a 2nd generation machine ie mainair F2a ect and the likes of,
You can pick em up for around 3-4k, and thats what I got myself with the Rotax 503 2 stroke electric start engine,
The 462 has a bit more power than my 503 and is water cooled, I think they may be a bit quieter and uses a bit less fuel, but I have heard people saying that they can be buggers to start,
Give me a call if I can help any more.
Nick in Cheshire.
You may be better addressing your microlighting questions here,
http://www.bmaa.org/forums/
P.S. were are you thinking of taking your flying course.