I don't particularly care about the typology of the conlang. I'd be okay with something very analytic or something very synthetic, something with many affixes or something with a lot of root compounding, something with European-style standard negation (a single invariable particle before or after the verb) or something with a more exotic kind of standard negation, say, negative inflectional affixes that have a different tense system from that of positive (non-negative) verbs (cf. Mandarin bu4 and mei2, which don't match directly with positive zai4, zhe and le).

Just don't make the vocabulary have too many unpredictable stems per word. Learning another Ancient Greek with 6 stems per verb, rather unpredictable for most roots, will make me unhappy. 1-2 stems, and maybe 3 for a few words, is as far as I'll go...