Identifying Alenco aluminum window parts

I'm afraid I can't possibly tell from these pictures what seal and glazing bead you mean. Alenco windows have been known to use our 58-127 or 58-183 Weatherstripping, but you'd need to compare the end profile to see if either is what you need. For Glazing, some Alenco windows use the 55-161, but again, comparing the cross-section view would be best. 

It looks like you have spiral balances in this window. If this is a non-tilt window, then to remove your balance, follow these steps: first, unscrew the balance from the top of the jamb, and then carefully unhook the balance attachments from the bottom of the sash. I suggest using needle-nose pliers to keep a good grip since it could still be under tension. Once the balance is loose, you should be able to pull it through the top of the jamb.