help finding wool for crochet

[incywincyspideragain]

I'd like to make a star blanket from a pattern that I have in a book - it appears to be american (I live in UK) the wool is NaturallyCaron.com 75% microdenier acrylic and 25% merino wool - what would be the equivialent? house bound at moment and was trying to do some online shopping I'm new to crochet and in the past have tried to do it with something thats too fluffy so any advice would be good!

That wool seems to be roughly an aran weight. Wendy aran yarn like this is a similar mix of fibres.

Does it tell you the knitting gauge? How many stitches &rows to form the standard 4 inch square?
Once you know that, & it usually tells you on the pattern or ball description, it's a simple matter of substituting any yarn that you like that knits up to the same gauge.