Gabriel, in this case you won't need a navigator. The topic of IFR vs. VFR is a bit murky: there is no official stipulation you have to fly IFR, but if you fly VFR, you'd better be prepared to follow IFR-like procedures, and will you certainly need all the IFR plates for ULLI (they are available from Jeppesen). You can also file a VFR-to-IFR flight plan (so that you switch to IFR upon crossing the border) but put "REMAIN IN SIGHT OF THE SURFACE" in the remarks box, so that you will effectively keep flying VFR. You can even try filing VFR, too, and see whether Eurocontrol approves it. I spoke to the briefing room boss at UMKK, who said: "If we get an international FPL from Eurocontrol, we will service it". To my question: "So, if my FPL has been approved by Eurocontrol, does it automatically mean I am all set and legal no matter what?" he said "Yes."
And speaking of Helsinki, you will be obviously flying to EFHF, not EFHK. Their VFR procedures are pretty constrained by the proximity of EFHK, and ATC at EFHF is extremely rigorous and exacting, so do your homework.
Finavia publishes a 1:100000 VFR chart for the Helsinki TMA - it's quite useful.