Wouldn't it be best not to mix brands on some parts?

Good thing none of them warranty performance parts.
COMP Cams® warrants that all of the products are free from defects in material and workmanship, and against excessive wear for a period of twelve months from date of purchase. ... This warranty is valid on camshafts only where new lifters and proper valve springs are used, such as those found in COMP Cams® Kits.
COMP Cams® - Product Support Information

www.compcams.com/Pages/360/support-information.aspx