Both cars take love and devotion.
Mechanical issues, rust and parts are issues.
I love the X1/9 but it is still a Fiat. You can beat on them hard but you need to be wary that there are some things you just have to do or it is catastrophic failure. Namely timing belts.
Also rust is a major issue in many parts of the country.
Both are hard to find low mike clean models and if you do they are not cheap. But in the long run they still may be the Best Buy if you find one.
The TR7 is a fun car but my money would go to a TR6.
Cars like this is why many people drive Miata’s. The same fun and much less fuss.
The truth is most sports cars take love care and money but the drive is the reward.