In specific answer, to your question on the 'Y' connection of two strips in parallel, the two are each simply a 12 volt device, so yes, you can just hook them up. Those numbers sound a bit high, for a bedroom filled w bright light.
Uhh, instead of hooking everything, like two strips at 5 amps apiece, looking for a 10 amp capacity psu, why not have two separate systems, each could then use those 7 amp PSU s you are thinking of using?
But, again, as long as your two strips are '12 volt powered', or any 12 volt device, like a fan, don't really interact, unless they share a 'load limiting' resistor. That isn't a complete answer, as I don't know if that type of LED strip has it's own integral load limiting resistor, and I don't know if the strips themselves do some partially in series, or if all are parallel (more likely).
As those strips are sold without PSU, does the info spell out a typical recommended PSU type ?
Otherwise, you are kind of left on your own, there, in terms of setting up for the proper current wanted.
Oh, and plus you (me also) need to start considering some real power in any load limiting resistor, which can turn out to be 10 ohms, at 5 amps... That's some large power resistor, at 250 watts, if I got that right.
Another issue, is that p/n strip the type and looks that you want ? I've often installed whole sets of parts, only to discover a much better item the next week.
I think I would start with a few strips, separate, and probably forget 'serial' connections if you want regular brightness. After all, 12 volt strips are for using 12 volts...(sorry, I can be a jerk sometimes, not your problem )
AND, can the layout be done, all with same length strips? You save some trouble there, as the whole task is separated into sub-sections.