Bad struts? Need some advice/help

ok so I have 90 5.0 with completely stock suspension yet..from what i can tell..def. the shocks and struts..don't know about springs, but im guessing they are..
For awhile, when i start gaining some speed..like probably over 40mph...my wheel hopes up and down..vibrates..its not a shimmy to the left and right, its up and down...
Would this be my struts being bad?? i know my rear shocks were leaking too so..
I'd like to do my shocks and struts, but I don't have tons of money, and I don't need anything crazy... I hear kyb is pretty basic...or tokico hp's?? What would you reccomend? I don't have money to spend on springs, so im leaving the stock springs in...so whatever setup would work best with those i guess..
Also, I've never done shocks or struts, but I mean i did brakes and i rebuilt my engine and stuff so I know some stuff.. Is it a tough job?
And while im in there with stuff apart, is there anything i should be replacing at that time? I dont need crazy upgrades, just basic stuff to help improve and give me a sweet ride... I'm not familiar with alot of suspension parts, so a write up somewhere would probably be nice..
Thanks!

tierods really???

yea thats what i mean, the steering wheel shakes up and down fast...
i don't think its a balancing issue...
would no one say thats my struts??? if they are stock, thats 17 years old..

is it cool to keep the stock springs in there tho? i dont have money for them...
also is there anythign else i should replace while im there? like when im buying 2 shocks, and 2 struts, is there anythign else i need...for replacing.. i know theres bushings but i have no idea where they are and/or for... im not good with suspension.