Adamant,
Firstly, I'm pretty certain that if you're in Kent the nearest place to learn to fly microlights is
here. I know some of the people there, and they're a good friendly club.
Secondly, for what it's worth I fly 3-axis microlights, flexwings, and light aircraft. I'd hate to give any of them up and certainly wouldn't talk you out of any particular route. For sheer fun (if not practicality), flexwing wins every time; for the joys of long trips by air in comfort with baggage I use a light aircraft. 3-axis microlights lie somewhere in between but have their own pleasures.
If you want to fly and money is limited, then I'd strongly recommend going the microlight route. The day-VMC-UK limitation is irrelevant since no cash-strapped PPL is ever properly current in night-IFR anyhow, and there is no particular problem flying outside the UK (I know that the microlight club I've linked above nip over to France regularly).
For long distance flying - it's possible, a review of any of the high street flying magazines will sooner or later throw up articles along the lines of "how I flew to Iceland in my 3-axis microlight", or "how I went to Finland and back in my flexwing". It'll take longer, but that just means more flying - I see no problem there.
Costwise learning 3-axis or flexwing microlighting will be similar. Subsequently however £3k will buy you a reasonable second hand flexwing, £6k is the starting point for a 3-axis (there are options to rent, syndicate, etc. but most of us like to own). For a serious 2-seat touring microlight you are looking for £15k+, but in a syndicate that's not much each.
My advice, go along to Medway, do a trial lesson in each of 3-axis and flexwing, and take it from there. But don't hold on for a couple of years to get an expensive licence that you might not then be able to afford to use anyhow.
G