paypal checkout with mixed billing type products

Question

I have, in my opinion, pretty complex order case to implement. Paypal was choosen as a solution, but I can't figure it out how to implement it properly using express checkout (or anything else, but I am not sure what is proper to use).

Final order that can consist of (most complex example here):

1. subscription A with 1 month free trial - 100$/year
2. subscription B without free trial - 200$/year
3. initial payment for entire order - 50$

Requirements:

1. start of the whole order can be postponed due to some factors (I can set PROFILESTARTDATE to the given date)
2. all subscriptions in the order can be either monthly or yearly, so case where subscription A is paid per year and subscription B per month IS NOT ALLOWED
3. whole order must be processed in one paypal redirect (paypal page with products listed where client can login to confirm the order)

My problem:

1. in that order subscription A starts 1 month later than B but I can only set one PROFILESTARTDATE
2. I could use TRIAL*** parameters (like TRIALBILLINGPERIOD) for subscription B but I can only set one such parameter per paypal request for express checkout, so same problem as above

What would be a best option for such case ?