I own a 1.8 20V non-turbo and i quite like them. Ok, it's not gonna pull your face off but they are quick, smooth and nice to drive and on paper not that much slower than the turbo (125bhp or 150bhp for the turbo) Only thing i will say is the turbo is much more tunable in terms of re-mapping etc. If you're just gonna keep it standard, maybe go and test drive one and see what you think.
Like Richy said in his previous thread, they stopped making the non-turbo a few years back so if you find one it will be a few years old but you should get a good one for your cash. I Paid 6K a year ago for mine, 1999 T Reg, spotless, just under 60K on the clock, full VWSH. Problems wise, apart from the various common faults every Mk4 suffers from (MAF, Door Lock Mechanism, Window Regs, Lambda probe as i've just discovered) you shouldn't have any problems. If it's done around 60K check the timing belt's been changed cause it will cost you £300 to get it done.
Hope this helps.