Depending on what you need available sans audio pauses and with perfect tails, many use an additional device or two with their FM3's to save CPU (typically Reverb, OD, or Whammy etc), and many external devices can be powered via the FM3's FAS Link connector as well (1A at 12V is available if you're not using a Fractal FC controller, and assuming you're handy with a soldering iron other voltages can be obtained).
Also, if new to IR's and familiar with the Two Notes Cabs with real-time control over mic positioning, you can incorporate your Two Notes Cab-M too.
The FM3 is CPU challenged in some respects for large kitchen sink type presets, but mine reliably runs the following...
2 Inputs, 2 Outputs, Wah, Amp, Mixer, Cab (2 standard IR's), Pan/Trem, Pitch, Send, Return, 2 Delays, Multi-Delay, Vol/Pan, Plex-Delay, and 3 Shunts, along with automated Tempo from Ableton LIVE, 2 Stand-In Switches, an Envelope Follower, a LFO, the Arpeggiator, 2 Gates and 2 GEQ's (via the I/O's), and a few Control Switches and Scene Controllers.
...all of this at 77% - 78% CPU on average, with 81% - 82% peak on one Scene with the Pitch Block doing smart harmony, and the FM3 is stable on all Scenes (with a Marshall 2203 tube preamp in the FX Loop and the Amp Block providing a really good tube power amp sim). The FM3 is happiest with the CPU usage under 80%.
That said, if you're primarily recording and if can you split everything into separate presets, then CPU should not be much of an issue. The new FM9 has double the CPU if need be (and the AFX3 double the FM9).
Good luck, have fun!