First of all:
Welcome to the forum!
Second: It is a little unclear (to me!) what exactly you mean by "I've decided to bite the bullet and buy a new one. " Do you mean buy a
new harddisk to replace the dead - you are you saying that you consider buying
a new laptop??
In either case, first go to
Warranty Lookup and insert the model number (4-digit) and the serial-number (7-to-8 digit), found at the bottom of your T43. Then, see if your damaged T43 perhaps is still under warranty? If you are really, really lucky, it may be (even!) covered by
ThinkPlus warranty service plan, incl. Accidental Protection (a warranty-extension), which means that it is covered in case of such an accident you describe.
But: Do you entirely rule out having it (the laptop) repaired? If you read on this forum, you will find a wealth of people who have dropped etc. etc. their ThinkPads, with no permanent damage!

Again... you may be lucky that it is only the HDD that's gone...
If you decide to go for a new ThinkPad (and of course stay with ThinkPad's if you now know that you like them, too!), then you may check the
Marketplace of this (outstanding!) forum, or go to eBay. If you want a
creme-de-la-creme ThinkPad (= instant and eternal happiness!), you should get a 15" with the famous FlexView/IPS display... believe me, this is as good as it gets!

On Sunday evening, a friend of this forum won a 1.8 GHz 15" T42 FlexView/IPS on eBay (and even having 1.5 year of remaining warranty) for only $416 + shipping, so watch out! ThinkPad's go cheap at eBay; a few minutes ago I saw a T43 being sniped for $395 -
this one (note that it is said being a T42, which is wrong - according to the model number it is a T43, check for yourself,
this one). As I type this, yet another T42 is approaching end-of-auction at eBay; don't know how high it will go... see for yourself,
here.
Update: The T42 just went for $315 + shipping which surely is cheap (depending upon the condition, of course, and whether if there is any remaining warranty etc.). Note the last-second bidder who won... yet a sniper in auction, again!
A lot of ThinkPad's seems to go every week on eBay.
Note: If you bid there, wait until some 5 (or max. 10!) seconds before end-of-auction with submitting your bid... that's the way to win (see for yourself the "bidding history"; the last-second snipers always win!). Don't bid very much earlier, doing this will only put other bidders (more!) alert, and start or escalate a bidding-war, and that you surely won't want!
What T4x (or T6x?) to get? Depending on your use... some are happy with T42's (incl. I!), whereas others are happy with T43's (although some of the latter have been reported to be somewhat noisy, but this to some extent can be cured). T6x's come cheap these days, e.g. have a look at the present sale at
Lenovo Outlet... new T6x's comes from
below $700!! Read on this forum about people's experience with the various ThinkPads. Of course, your budget will set a limit.
In any case: Good luck with either having repaired your broken ThinkPad, or getting a "new" one!
Best regards,
Johan