All-year wool trousers

I'm kinda lost and need your help. Long post, thanks so much if you read through it. I'm invited to a wedding in April. I don't have a suit, but I do have a navy wool-silk-linen-cotton sport coat. I figured I'd wear that with mid grey wool trousers, brown suede loafers and a white silk pocket tie, something similar to the picture attached. (I don't think the event is very formal, they didn't specify a dress code, and people in general dress quite badly around here, unfortunately.) Now my problem is I don't have any pair of tailored trousers. I've explored my options but haven't really found the answer. I find odd trousers harder to find 2nd hand than sport coats, and I'm exposed to a limited 2nd hand market here in Central Europe. I'd like a pair with high rise and straight leg with a reasonable leg opening (20cm+). I'd be OK with Natalino's prices (~230 EUR), although they don't seem to have a pair which is applicable for year-round wear. They have woollen flannels and they're coming up with tropical wool pairs for S/S. Moreover, there's no mid grey option for the tropical wool ones, only charcoal. Going up from Natalino's prices it'd come close to the price I'd need to pay to a tailor I talked to here to make a pair for me (~150 EUR labor cost + cost of the cloth). So full price of Cavour, Berg&Berg trousers (these are the brands I know) would cost the same or more to have a pair made here. So, I think it wouldn't make sense for me to go higher in price than Natalino's in RTW.