Is the Giants portal compatible with the original game? Now that I got a portal for so cheap, I hope I can just pick up the first game's disc on eBay and not bother getting a second portal.
Found it at a St Louis, MO Target for $13.98.
Oh, and the Circle Pad Pro XL is a little cheaper on eBay. It's $20 plus $5 shipping from Nintendo, but eBay sellers right now have it for $21.50 with free shipping.
A few of the PSP Lego games were ports of the console ones, but for awhile now they've been making a much downgraded game for the DS and then porting that version to the 3DS and Vita.
On the subject of controllers, a Dualshock 3 with the Sixaxis app works great. It supports touch mapping, which means basically every game works with it with a bit of setup time.