Should I upgrade my MacBook Pro? And am I upgrading correctly?

Hey, I own a 15-inch, Mid-2010 MacBook Pro. I'm currently thinking about upgrading the RAM (from 4GB to 8GB) and the hard drive (from 320GB to 1TB). The only thing that is holding me back is my battery life. I'm currently at 1103 cycles and the condition is reading 'replace soon.' Now, I was reading up on battery replacement, but wasn't able to determine what I should do about it. Is it worth upgrading my MBP if the battery is getting closer to the end? I don't really know the whole process of replacing the battery.

Also, if I do decide to upgrade, are these the right parts?

RAM: http://www.amazon.com/gp/product/B005LDLVAO/ref=ox_sc_act_title_1?ie=UTF8&psc=1& smid=ATVPDKIKX0DER

HDD: http://www.amazon.com/HGST-Travelstar-2-5-Inch-Internal-0J22423/dp/B00B4QESVQ/re f=sr_1_3?s=pc&ie=UTF8&qid=1380031668&sr=1-3&keywords=1+tb+macbook+pro+hard+drive

If they are not, could anyone please help point me in the right direction. Thanks.

Also, when replacing the HDD, I know I have to clone my original hard drive, if I clone it onto a blank 4TB or a blank 1TB external hard drive, will that external hard drive still be usable after I finish the cloning and the installing of the new HDD? I know it will be erased, but after I get the clone on there, I can still use external hard drive again after that right? It doesn't just become consumed with the clone, right?

I'll really appreciate any help you guys can provide, thanks!