Adding second loop for radiant floor heat with a Caleffi Mixing Station

consoleb

Hi, We have an old house with a 8 year old Burnham gas boiler. In the basement there are two sets of pipes running the perimeter with one set feeding hot water radiators on the first floor. The other set of pipes is not connected to anything. The guy who lived there before us probably wanted to put radiators on the second floor. There are two pumps each one feeding one of these loops coming off the boiler. I want use the second pump to heat two rooms on the first floor that have very little heat, using 1/2 pex-al-pex under one room between the joists (it's a 13X13 kitchen above a crawl space), and in the adjacent room which is slab on grade put the pex above a insulated subfloor then cover it with 2-3" maple hard wood flooring. I have a couple questions. Can I get a Caleffi Mixing Station and connect it to the pump coming off the boiler. Or do I just fun the pump to a minifold? I thought the mixing station would help control the heat under the hardwood flooring. Another question, can I run the 1st pump into the pump built into the mixing station without damaging one of the pumps? Or should I just get a variable speed pressure regulated pump and go straight into a manifold. There will be probably 4 loops. Sorry for all the questions but I need to do this myself due to limited finances.
Thanks for any help.
Brian