Playroom Planning

The time has come to transform our dining room (which has never had dining room furniture in it) into Mason's playroom.  The toys are taking over our living room and I know the toys will only multiply and become bigger and we will no longer be able to contain them in the living room alone.  
I have mixed feelings about this transformation because the dining room is actually part of our entryway, but I figure Mason is only going to be little once and when he's grown I can have a formal dining room.  
Thankfully, Brandon's dad has offered to build us a custom toy shelf and to also make us a custom rug from a carpet remnant.  Yes, we are very lucky that he is so handy!  Here is a picture of the shelving unit that he is building, only ours will have one more row of shelves:

Contemporary Kids design by Other Metros Architect ALVAREZ-DIAZ & VILLALON

I'm pretty excited about the big drawers along the bottom to store all of the odds and ends and then he is going to make the shelves adjustable so we can accommodate different sized toys.
I also need to start looking for affordable light fixtures.  I like the bright colored drum pendant that is pictured with the shelving unit but I'm having a hard time coming up with a color scheme that blends with the rest of our house and lends itself to a playroom.  I do like the patterns on these shades, but again I'm not sure about colors.

Same goes with art for the walls - I just don't know where to start.  Here are a few prints that I found that I really like, but none of them really go together, or at least it doesn't seem like they do.

{yes, an ode to Koby!}

{definitely for a boy playroom}

{I like the style of these prints}

I want this to be a very economical makeover so hopefully I can come up with a few good ideas to get this project started.