Incrementing Brute Force Attack?

Hello!

I'm fairly a newb to oclHashcat and recently purchased a NVIDIA Geforce GTX 970 for gaming and cracking hashes. I just have a few questions before using cudaHashcat for password recoveries and such.

1. Is the GTX 970 (ZOTAC AMP! Omega) a good GPU for cracking hashes?

2. How would I go about using an incrementing brute force attack on IPB 2+ hashes? What I mean when I say this is to start use a mask or some sort for both lowercase and uppercase letters and numbers without having to manually change the mask or any options once the other is completed. Example:
a
b
...
z
0
1
...
aa
ab

But here's the catch. I need to start at 3 characters and increment to 32. Would using Hashkiller.co.uk's HashcatGUI help? What would the options be set to?

Thanks! Happy New Year!