The Finnish Army has a great need for new equipment as far as I know. I know about attempts to fix the ATGM problem with Eurospike or Javelin, but the survivability of the artillery and likely also the EW equipment need to be addressed. Towed guns are almost useless for national defence nowadays.
That's only the hardware issues. Improvements of reservist and marksmanship training as well as general increase in training spending is likely much more effective than expensive planes.

Otherwise - it's quite common to upgrade fighters, and an integration of AIM-9X/IRIS-T/Python5, AMRAAM, HMD, new radio tech (better ECCM), new pylons (with integral chaff/flare dispenser and missile warning sensors) and finally a towed ECM pod would improve the fighter to almost state-of-the-art.
Old F/A-18 have furthermore a poor INS that needs a long calibration on the ground - that should be replaced as well.

I wouldn't assign the long range strike mission to the Hornets at all. Instead, I'd simply ask PR China for some of their MRBMs, one of which seems to be close to Iskander in accuracy and would be a much greater threat than a few normal fighter-bombers.

The backbone of the Finnish defence needs to be the infantry with sufficient indirect fire support, AT capability and a small armored reserve to counter breakthroughs of mechanized OPFOR.