Can anyone provide me with their recommendations on which tool is better?  

Your best bet is to find your local REIA, which you can search for on nationalreia.org. 

Zillow suggests that I spend $29.99 for a premium listing, promising that renters will see the listing more often because it appears higher in search results.

Are there specific tools or systems that you recommend for remote management that could help streamline operations?

I have been browsing all the tools here, and just trying to become familiar with the site and the treasure trove of knowledge and tools that are available here. 

Yes Lilach, there's been a number of successful BRRRR, your why for venturing into Jacksonville market for BRRRR should guide your search.

Here are a few below:Generally, buying through your personal name can reduce the interest rate - commercial rates on LLC mortgages are usually higher but you can research thisMost LLCs on incorporation don’t have any credit so it may be difficult to find. a lenderIf you own the property in your personal name you are exposing yourself to more risk and will want to transfer the property into LLC as soon as you canIf you own property in your personal name and transfer to LLC the lender may not allow or can call the entire loanLLC or personal ownership you need insurance.If you search the forums for this topic using the magnifying glass feature in top right corner of your screen on BiggerPockets you will find a lot of discussion on "Quit Claim" "Buying through LLC", "LLC or not" etc....

So even popular rent estimate tools seem a little inflated unless you're outpeforming the competition with what youre offering.

BP should run a reverse search to see who upvotes their posts. 

Both Facebook Marketplace and Craigslist are good places to search for off-market properties.