With that budget I would just get a 12" Surface Pro 3 Windows 8.1 tablet with a Core i7-4550u which has the Intel HD 5000 graphics core. It is released today (at least in the US) with a suggest price of $1,549. The Core i5-4300U version with the Intel HD 4400 graphics core starts at $1,299.
I had a Nexus 7 which recently stopped working. While I liked it at first I found Android to be rather limited for my needs. I am currently looking a Windows tablet, but I haven't found one that meets my requirements yet. The Surface Pro 3 is nice but I am looking for something smaller than 12 inches for the moment.