Saw the panels in the link; that's the kind I use too....and that's a far better price than my local farm store sells for too...about $35 ea last time I looked. I noticed that this company is out of PA...is there not a place in FL near you that you could purchase from? Check Lowe's or Home Depot for the 4x4's and tpost. Tposts should run about $4-5 average, but don't really need the heavy duty post. 4x4 will be a little more. For the tposts, they make a wire tie already shaped to go around them, or could just use a bag of chain link wire ties and bend yourself. Shouldn't be much of a cost difference in those. If you use tpost, get or borrow a tpost driver; it will save time and your back versus driving one with a 3 plus pound sledge hammer. I have one and it is handy and wellworth it since I tend to redesign and add fencing every now and then.
Either the tposts or 4x4's at each corner would be fine. But also put whatever you're using at each 8' point along the panels as they will give and sway some. Mix the posts if you want, the 4x4 on the corners and for a gate and tpost at the 8ft points. I prefer 4x4's for my fencing (now use one to hang my gate) but I use tposts for the fencing because it so much easier to drive a tpost in the sand here than it is to try to dig a hole in sand! That said I can get the tpost all set level vs. the digging holes and the sand keeps sliding back in the hole and I end up scooping the sand out and make it deeper by hand or with a garden tool. But my 4x4's that I have are 8' long and I set them 3' in the ground and don't use concrete and they hold my gates fine. The gates I use are either a chain link walk thru gate or a 4' aluminum or galvanized field gate with a peice of 2x4 fencing tied over the bars to prevent escape. Also, not using concrete makes it easier for me to move and redesign if I need.
The next thing I need to build is a feeder or barrier for my goats to keep them from walking in the feed trough and across their food...something they can get their head through and not the rest of the body! I've been putting it off because work and the weather has caused delays, but today looks like a good day to build.
Check craigslist in your surrounding areas for supplies as well. You may come across something that you need or something that may come in handy.
Good luck on your fence building and let us know how it turns out.
Either the tposts or 4x4's at each corner would be fine. But also put whatever you're using at each 8' point along the panels as they will give and sway some. Mix the posts if you want, the 4x4 on the corners and for a gate and tpost at the 8ft points. I prefer 4x4's for my fencing (now use one to hang my gate) but I use tposts for the fencing because it so much easier to drive a tpost in the sand here than it is to try to dig a hole in sand! That said I can get the tpost all set level vs. the digging holes and the sand keeps sliding back in the hole and I end up scooping the sand out and make it deeper by hand or with a garden tool. But my 4x4's that I have are 8' long and I set them 3' in the ground and don't use concrete and they hold my gates fine. The gates I use are either a chain link walk thru gate or a 4' aluminum or galvanized field gate with a peice of 2x4 fencing tied over the bars to prevent escape. Also, not using concrete makes it easier for me to move and redesign if I need.
The next thing I need to build is a feeder or barrier for my goats to keep them from walking in the feed trough and across their food...something they can get their head through and not the rest of the body! I've been putting it off because work and the weather has caused delays, but today looks like a good day to build.

Check craigslist in your surrounding areas for supplies as well. You may come across something that you need or something that may come in handy.
Good luck on your fence building and let us know how it turns out.