best method for two blog styles on one site

I’m in the middle of redeveloping my website, https://portfoliosfriend.com and I am going to have two sections. One as a thumbnail showcase, and the other as a normal blog. Currently to achieve this I am using two WP installations with the same database. however, in my research I’ve found ways to change the styles for different categories and was planning to restyle my normal blog parent category to achieve this so I don’t have to install WP twice.

I’d like to hear some opinions on the good and bad of either installing WP twice, or using one install with differently styled categories. Thanks everyone! ??