Air handler sizing question

[EternalStudent]

We are in the process of having a new system installed. Tonight I went up to check out what they had done and had a question: I was told by one person who came to give us a quote that we had to get a new air handler because the old one would not match the new condenser. I was told that he knew they would not match because I had a 17.5" cabinet (he called it a B cabinet) and I needed a C cabinet. We went with a different guy (who also said we needed a new air handler) - but as I look tonight, I notice that the new air handler is still a 17.5". Does this mean that the new system does not match? Through research I have been able to figure out that it is a 3.5 ton (which matches the outside unit being installed)...but does the cabinet size need to match like the other guy said? How can I determine if the air handler and condenser match? The new unit models are as follows:
Bryant Air Handler - CNPHP4221AT
Bryant condenser - 310AAV042090
THANKS for any pointers - I have learned so much through this, but have so much more to go

[dan sw fl]

http://www.ahridirectory.org/ahridirectory/pages/ac/defaultSearch.aspx

Request the AHRI number

and/or
Use the link

[EternalStudent]

Thank you for the link! Will be doing some more research.

[JamesCPH]

Are they replacing your outdoor unit also?

[EternalStudent]

yes - with a Bryant also (Model #13ana042-c). I know that I read they needed to all match - just am still trying to figure out how to know if these do in fact all match (other than just taking the word of the sales guy). Thanks for any advice - I am still trying to find the AHRI # as previously suggested.

[dan sw fl]

http://www.general.hvacpartners.com/wcs/prod_physicaldata/0,2734,CLI1_DIV42_ETI5367_PRD793,00.html

Furnace
310AAV042090

[warm]

The A-B-C cabinet are different sizes to fit the duct work the coils in side are rated for tonnage the smaller the cabinet the taller the coils are to match the rating( heat transfer
area will be the same on all the sizes to match the tonnage) you would match the cabinet to the closet/plenum- wouldn't use a C cabinet (21") on a 17 1/2" plenum would
you?