How to choose an FPGA for lock-in amplification functionality

Hi all

I am new to FPGA and hardware design in general. I am trying to determine which FPGA to purchase. My application is to create 8 to 10 parallel lock-in amplifiers in order to analyze signals coming from an atomic force microscope. The lock-ins should have specs similar to this product: http://www.intermodulation-products.com/pages/im-lockin/specifications.php

What is the best way to determine which FPGA product would best suit my needs? Do you suggest that I create the entire design first in Quartus II and then based on the analysis choose the FPGA product? Or can I made a good choice on which FPGA product to purchase just based on knowing what my application is and what characteristics I want for the lock-in circuits? It seems to me I probably want to go with a Cyclone series product, but I'm not absolutely sure I don't need something higher end.

I am currently going through the Altera FPGA training courses to learn as much as I can about FPGA programming and the Quartus II software, so it likely will take me some time to have a finished design, and I have a relatively short timeline for purchasing equipment.

Thanks for any advice you can give.

Erin