Generally, broadband bass absorbers go in the front corners and centered on the wall behind you. You have restrictions in both of those places (window, door, shelving). The side edges of the front wall would be the next best choice.
Reflection panels are used at first reflection points of the side walls and ceiling. You can find these using a 2nd person and a mirror pretty easily.
Yes - these products are readily available from us and from other companies.
Bryan