I trained in a "steam" aircraft for my CPL, however a DA42 for the IR. First time passes in all, no issues on either layouts. However I have items such as Luiz Monteiro, notes on the G1000 and familiarity on the DA42 performance to hopefully get upto scratch without too much remedial training
There shouldn't need to be any training, it's only a proficiency check, just do it. If the examiner wants any items repeated, he'll get you to do them there and then.
Any FNPT2 will be fit for the purpose. I know this is your first one, so you are in the dark, but this will be nothing like the initial IR test you did. Most examiners will realise you aren't too current, also realise that you aren't about to go out tomorrow and fly single pilot IFR for anyone without some serious training beforehand, so most will be pretty lenient and get you through, with a few pointers thrown in too.
I did my initial IR in a beech duchess, let it all expire then did a retest in a seneca. Never even been near one before, just read the POH and got on with it, it's not rocket science, an aircraft is an aircraft at the end of the day, if you've got a class rating to fly one you should be able to.