Professional WordPress site to meet requirements.

I am looking for a website because there my current SquareSpace site is good but lacks some elements. Current site: www.genuine-stagram.com

My issues:

1: better design for the navigation of the blog.
2: better payment screens so more of a deign for the PayPal links
3: forms to have a better deign and the ones on my site don't stand out as clear as I would like.

My site needs to be a mixture of promoting my service I offer to clients all over the world and also to promote my clients through a blog on my site as you will see from the blog in the current site.

Here are two links of template that I like but I have been told from one developer here on PPH that these are basic themes and won't be as customizable as I would like, i.e. my 3 issues above.

Designs I like:
1. https://wordpress.org/themes/colormag/

2. https://wordpress.org/themes/zerius/

I look forward to your replies with ideas and solutions if needed to meet my needs.

Terence

p.s. also please quote reasonably cheers