Check with extremedimensions.com, they have a mugen style kit. They have it pictured on an 88-91 CRX just for show.
Check EBAY! I have seen '84-'87 CRX body kits up for auction several times for around $350-$400.
In my opinion the kit from Andy's Autosport is kinda' lame looking.
Also... Ever notice how the body style of an '84-'87 Civic/CRX is alot closer to a '88-'91 Civic HB than it is to an '88-'91 CRX?