Some points to note:
- Unless you are doing seriously CPU-intensive work, you won't notice the difference between the i5 and the i7.
- Unless you are doing heavy video editing, or running multiple virtual machines, you don't really need 32GB of RAM.
One other thing - don't pay Apple's prices for the 32GB of RAM. In the UK, they charge £480 for 32GB. You can get a decent 32GB kit for less than £230.