To be honest, Aloes generally are quite adaptable and would be amenable to many compost types as long as free drained. I would use an approximate mix of three parts multi-purpose (either), one part horti sand and one part perlite.

For many succulent plants I would normally use a compost with loam added too for extra "depth" but the above should be fine.

If you wanted to add loam, buy a bag of top soil and use two parts multi-purpose with one part loam added to it plus the one part each of horti sand and perlite.

Thanks Fractal, is topsoil loam then? I cant find, just loam, loam searches i've made on the internet just come up as topsoil. In many of the RHS books i've bought its often mentioned to use loam but i have not been able to find bags of loam at the gardencentre.

Loam is a soil made up of approximately equal parts sand, silt, and clay...BUT...in gardening it has come to mean any soil rich in organic matter. In the books, they are probably expecting you to go out in the woods and dig up that lovely loose black soil that has been forming there for the past ten centuries, like they did without thought in Victorian times--the vintage of the books, or the books' authors' teachers! Probably better to make your own with good garden soil, spiked with sand, clay, and/or the fines sifted from compost, as needed to tweak the texture. If it was me, though, I would sift the compost and use only those particle sizes from 2-5 mm, along with horticultural sand and pumice or fine volcanic cinders--substituting perlite in the absence of the last two items. About a 2-1-1 ratio for aloes and most other leaf succulents.

Thanks for both of your informative replies.