system requirements for a new pc

[thufir]

I think that I need a new, or at least newer, computer.  This one uses 

product: Intel(R) Pentium(R) 4 CPU 3.00GHz

and is a bit memory constrained:

thufir at mordor:~$ 
thufir at mordor:~$ free -h
             total       used       free     shared    buffers     cached
Mem:          1.9G       1.9G        15M       200M        17M       1.1G
-/+ buffers/cache:       852M       1.1G
Swap:         2.0G       524M       1.5G
thufir at mordor:~$ 



I typically have the following programs open:

Netbeans (memory hog)
Thunderbird (can peg the CPU)
Firefox
pan newsreader
pidgin IRC
terminal

I was thinking of something like:

    Our desktop computers come installed with Ubuntu 12.04.5. Macs will 
be installed with Mac OSX Snow Leopard, Yosemite, or El Capitan. We do 
not sell computers with Windows operating systems.
    Prices include one power cord.
    In order to keep our prices as low as possible and minimize waste, 
prices do not include mouse, keyboard, monitor, or other peripherals.
    The following specs and prices are guidelines. We can tailor the 
machines to match your needs - please speak to the store coordinator or 
the build coordinator. 

Intel Core2 Duo w/ 80GB HDD, 2GB RAM - $50
Intel or AMD Quad Core w/ 160GB HDD, 4GB RAM - $100
Intel or AMD Quad Core w/ 200GB+ HDD, 8GB RAM+ - $150 - $180
Intel Core i3 - $200 and up
Intel Core i5 - $230 and up
Intel Core i7 - $290 and up
iMacs- $150 - $500 


Probably anything with 8GB RAM and quad core should be sufficient?  



thanks,

Thufir