Given the price difference there is $15-20 (less than the difference at B&H - B&H wants $190 or so for the Di Macro version), definately go for the Di LD.
Less important than the macro capability is that the Di version has improved coatings on the optics - the idea behind the Di lenses (and Sigma's DG lenses), i.e. lenses that cover full frame but are "optimized for digital" is that the sensors of most digital camera sensors are far more reflective than film, and so tend to make the problems of cheaper lenses more obvious than film does. (A perfect example would be my first-generation Sigma 28-200 f/3.8-5.6 - it gave good results with film but HORRIBLE contrast when mounted on my K10D).
Thanks for the Amazon link - they are priced well below B&H (that's VERY rare) and it appears to be a direct offering from Amazon, not an affiliate vendor. (Many photo products on Amazon are from Adorama - not that Adorama is bad, but just like B&H, I get charged sales tax if I order from them since I am a New York State resident.) I had been considering the Ritz Camera Quantaray-rebadged version of the 70-300 Di LD because it was cheaper and no-tax, but I'd rather order the Tamron-branded version for the same price from Amazon themselves.