hey guys

i'm thinking between getting a Epiphone Special II and a LTD EC10. any of you guys have experience with either of these guitars? i play a lot of hard rock and 80s metal...

or should i just replace the crap pickups in my cheap knockoff strat with a tesla or dimarzio double-rail?
I would say save your money and do neither, you'll appreciate it much more if you actually upgrade rather than just throwing money at the problem in a relatively piecemeal fashion.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

could you recommend some mid-range guitars for me to upgrade to?
It's a waste of money going for those guitars then upgrade. But first of all, where do you live and what is your budget? Also, what's your current amplifier.

ESP Standard Eclipse I CTM VW
ESP LTD Deluxe H-1001
ESP LTD Deluxe Viper-1000 STBC
ESP Edwards E-EX-100STD
Warmoth Paulcaster "Tiger"
Tanglewood TW170 AS
Vox Tonelab ST
Blackstar HT-1R

Yeah, you'd be better off saving the cash and upgrading to something a little better later on.

To answer your other question - it depends on your budget. "Mid-range guitars" mean different things to different people, and price-wise it's a pretty wide range. But in general a better step up from the two guitars you mentioned would be an Epiphone Les Paul Standard, or an LTD EC-200-series. New price of those is somewhere around $400 but you can find them cheaper if you look used.
Current Gear:
2002 Gibson Les Paul Standard
'57 AVRI Fender Stratocaster
MIJ Fender Jaguar Special HH
Marshall JVM410
Vox AC15 C2
Ugh. I don't recommend the absolute cheapest guitars offered by a manufacturer, especially when you're talking about the cheapest of the budget line companies (Epi and LTD).

Give us your budget, style of music you play/want to play. I also do not recommend putting good pickups in a cheap guitar. It won't raise the value of the guitar by much when/if you sell it.
There are literally countless "mid-range guitars". What kind of body shape do you want? Do you want a tremolo system or hardtail? Active or passive pickups? Wood? What kind of amp do you have? Etc etc etc. Give us some direction over here bro!
Agile AL200, 3000, etc.?
Airline 3P Deluxe
Gibson SG Special w/ SD 59's
Victoria MIJ 60's Electric Guitar
Martin DCX1E
Hughes & Kettner Tubemeister 18
Bunch of Pedals
Squier Vintage Modified Jaguar