Nice seeing some of your model cars!
Captain Ahab Jr- If you like Spark, check out Bizzare and Looksmart. They carry some different models but the detail is just as awesome. Almost all of my collection is Spark with some Mark43 (Japanese cars), Bizzare, and Looksmart. Excluding hotwheels of course!
Eric Hahl- that's awesome! Some of my friends just picked up some Mini-Z's and we're going to build a small track in the little man cave so we can race them. I haven't played with RC cars in over 15 years, feels so nostalgic!
Heel n Toe- completely agree with you on 1/43 scale for the same exact reason! I don't even want to count how many I have. Unfortunately I have a bunch in boxes because I have nowhere to display them.
herr_oberst- 1/87 is a really funky scale, hard to find, and for some reason the prices are quite high. I only have 2 and they're both the Porsche 919's. They're really cool though!