These are my specs any ideas on what cpu should I get?
Operating System
Windows 10 Pro 64-bit
CPU
Intel Core i5 6400 @ 2.70GHz 45 °C
Skylake 14nm Technology
RAM
16.0GB Dual-Channel Unknown @ 1066MHz (15-15-15-36)
Motherboard
ASRock H110M Combo-G (CPUSocket) 41 °C
Graphics
SyncMaster (1680x1050@60Hz)
4095MB NVIDIA GeForce GTX 1050 Ti (EVGA) 58 °C
Storage
931GB Seagate ST1000DM010-2EP102 (SATA) 30 °C
931GB Western Digital WDC WD10EZEX-00BN5A0 (SATA) 32 °C
Optical Drives
TSSTcorp CDDVDW SH-224FB
DiscSoft Virtual SCSI CdRom Device
Audio
High Definition Audio Device
If you want to upgrade your CPU and keep your motherboard with the DDR4 RAM, the best you can upgrade to is the i7-7700K or its non K variant!
I hope I could answer your inquiry.
If you update your BIOS to version P7.00, you can use any of the Kaby Lake CPUs, including the i7-7700 (33% faster per core, has HyperThreading), which is about as good as you'll get on that motherboard...& since that would be a really nice CPU, you won't get too much better performance even if you went to a Coffee Lake motherboard & CPU.