Need help building a PC build

Here’s the situation: my Pentium keeps overheating and acting up constantly, and honestly, I’ve reached my limit with it.

I'm looking to switch over to an AMD setup—specifically a CPU, motherboard, and RAM. My budget is roughly $267, though I’d definitely prefer to keep it as low as possible... I realize that might be a tall order since I'm not entirely sure what current market prices look like.

I'm really leaning toward avoiding Intel unless the price is just too good to pass up—maybe around $200... The specific model doesn't matter much to me, as long as it outperforms my current 3.0GHz Intel chip, or at least matches it if we need to stay strictly within budget. I'll need a DDR3 motherboard, and regarding RAM, more is better; I'd love to hit 4GB since I run CAD software, but if that's out of reach, I'll start with 2GB.

Any suggestions or advice would be greatly appreciated. I'm feeling a bit overwhelmed by all the options; there are so many different retailers out there and I have no idea where to find the best deals.

I found this combo at Best Buy... the processor seems a bit pricey to me, and I'm not even sure if it's actually an upgrade over what I'm currently using.
http://www.bestbuy.com/?naziv=procesor-...kl=050.603.281
http://www.bestbuy.com/?naziv=procesor-...kl=050.603.281
http://www.bestbuy.com/?naziv=maticna-p...kl=050.303.714
http://www.bestbuy.com/?naziv=maticna-p...kl=050.303.718

I don't think AMD has anything particularly smart in this bracket, except maybe the Core i3-4130 paired with $167 an FM2 motherboard for about $127 and 4GB of RAM, which brings us to $367

ASUS H81M-K motherboard (S1150, DDR3, SATA II, SATA III, PS/2, USB 2.0, USB 3.0, LAN, audio Line-In, Audi
Intel Celeron G1820
Patriot Sig. DDR3 1600Mhz, 4GB PSD34G160081

Total cost: $282 Best Buy

Honestly, I'd go with this Celeron setup since there's plenty of room to upgrade later on.

Could you help me understand why Intel... honestly, I’m a bit skeptical about them. Plus, the heat issue is a real headache for me; my room gets absolutely sweltering in the summer because it faces south...

Since I'm typing this on my phone, would you mind giving me a bit more detail regarding the processor?

Thanks so much!

It’s probably not an Intel issue, honestly. This chip runs cooler than any AMD I’ve used. You might just have a crappy cooler or some bad airflow in your case

You might want to consider swapping out the thermal paste and giving that heatsink a good cleaning... It doesn't have anything to do with whether you're running Intel or AMD.
Which Pentium are you actually working with?

Bottom line: that Celeron is your best bet for the budget you've got.
Your main move would just be upgrading the motherboard.
http://www.newegg.com/?item=motherboard-link

That same model from three years ago also features built-in USB 3.0, just in case you ever need the extra speed.