the wooden ones are nice, and more rigid, but quite a bit heavier than the aluminium ones.
Measure your ceiling height. It will probably be about 2400mm (8ft). If higher, some standard ladders will not be long enough (I have a three-segment aluminium one for a 3100mm ceiling). If non-standard, verify that your ladder can be adjusted to lock rigid at the height you need.
If you are weedy, not very tall, or your ceilings are high, you will find a lightweight one easier to use.
Look in the loft at how much unobstructed space you have where the ladder will slide or fold back, and check that it is enough.
If you loft is not already fully boarded, I strongly recommend boarding all round the area where you will be climbing on and off the ladder. If you have a place near you that sells ply and cuts it to order, work out what size pieces you need, and buy a 2400x1200 board of 18mm ply (I think it will cost in the region of £25-£35) and screw it to the joists using 35mm CSK screws. It is important the board are firmly screwed down so they can't move when you step on them.
It is useful to fix some strong grab handles near the top of the ladder. Invalid/disabled grab handles are widely available, as used around steps and in bathrooms. If you ask on Freegle you may be offered some.
You will need lighting. A good trick is to have a pull-cord lightswitch so the cord dangles at the opening, with a large curtain ring or similar tied to the end, easy to pull by hand or with a hooked rod.