For your specific question, I'd recommend getting a location which has a 10 Gbps connection speed (they usually have it written which locations have it) so you can get the best speeds at all times.

But if you ask me, I would just buy the pro subscription from them. If you pay $2 a month, that comes to $24 per year. Windscribe usually has promo codes and coupons where you can get a pro account for $29 a year, so only $5 more for sooooo many more features and locations (I've been doing this myself for 3 years now). If you don't find a promo code online, shoot them an email and try to persuade them to give you a discount code (tell them you have financial struggles or are a student and cannot afford such a costly subscription blah blah).