Seat & Tire Upgrade Links Inquiry

Good Morning,

Recently purchased a small frame G1 on a Walmart discount find, upgrade my from 70’s Ross paddle shifter road bike.

I’ve heard many upgrading to an Elita One seat post and new seat but I have no experience with AliExpress and some listings don’t show sellers names. Does anyone have the name of a reputable seller or a link?

I plan to ride mostly casually, without padded shorts, as I’ve done on the road bike, so looking for comfort seat.

Also, I’ve heard many upgrade tires to Rene Herse tires or similar. Can I do this without upgrading wheels? If so, a direct link to amazon or Ali express would be great for either or both.

Any other recommendations welcome.

Purchased and using:
Bag - https://a.co/d/0dlDfXZF
Phone Mount - https://a.co/d/0a4HelgW

Thanks all.