advice, please on converting ex-commercial steel hull vessels

[artnik]

My husband and I are looking into buying a large-ish ex-commercial vessel that is partly converted to a liveaboard.
I tend to look at Dutch built (small) ships of 25 m + because there is the space to have an office there and live comfortably. It is important that the vessel is sea going.
Our budget is limited and, inevitably, we are drawn to either decommissioned fishing trawlers (cheap) or converted boats that are too expensive.
Has anyone the knowledge and experience to advise on the minimum spec we should be looking for - we need to run a few computers on board and be able to cope with the engine/generator, etc. equipment on our own.
We have very little experience, but love boats.
Also, we are based in Europe (UK) and plan to cruise European and North-African waters.
Many thanks.