Camskill are where I have bought my tyres from for years and always recommend them.It seems like a reasonable price, but more to the point, it was the only place I found that actually seems to stock them so this is where I was intending to buy from. Seem like a fairly reputable outfit.
Personally, I despise budget tyres but the spec of the Landsail tyres are very good, in fact better than a lot of the top brands (fuel efficiency 'C' which is excellent, wet grip 'B' which is very good (but I always try to buy 'A' as I believe grip in the wet, and especially stopping distance in the wet is the most important test of a tyre as anything will be 'ok' in the dry) and the 68db for noise level is brilliant.
I know other members have used the Landsail's on their A2 before and rated them highly so I wouldn't be overly concerned about fitting one of those, especially as you already have them on your car so know what you're getting ?