I have a question related to hardware and a possible purchase

Currently i am running lubuntu on my core 2 duo 6500 4gb ram 512 mb vid ram nvidia geforce 9300m. Ok so basically i am trying to figure out if i should purchase another laptop for better performance definitely nothing over 500 dollars us. I am currently have a 250 gb hard drive on the laptop but i use my 500 gb external to boot lubuntu and honestly i am totally falling in love with linux all over again. (i've been putsying with it on and off since ubuntu 6.06 or so. I am not very well versed in programming but would like to get to know more as a side hobby if anything. I like to run my emulated games on linux, n64, ps1, gba,gbc,gb,nds,snes,nes,genesis, master system,saturn,i think you get the idea. i am also trying to replace a program in windows that i use frequently thats converts my downloaded comics into smaller sizes for my phone called comicrack. I was thinking i might be able to write a script to literally unzip/unrar the file resize the images and rezip or rerar it and saving about 60-75% of the size. The rest of my computer use is basic internet stuff like flash, pdf's epubs. So basically i know i do not need to the biggest of performance jump because honestly the graphics dont make much a difference except maybe to make sure i can run it on my monitor that is full hd 1920x1080p. other than that graphics requirement if its better than what i have it should do me fine i think. also if anyone can point me in the right direction for ps2 or gamecube emulation on linux if it is at all possible i would appreciate it. Oh and also i have tried sabayon i just do not like the fact that its harder to find pre-done binaries for it if it is not in the repository. Thank you very much and have a great day.