Which Acrobat offline version to buy?

Dear All,

I used Adobe Acrobat 8 Professional since the past 7 years. Now I don't have the installer or the keys. I need to buy an offline solution which I can reinstall on the laptops that I buy in future too.

My requirement is very basic, and I regularly used the following functions in Adobe Acrobat 8 Professional;

• Make and Fill forms
• Alter text in PDF documents, remove or add images
• Typewriter function
• Export to MS Office, and JPG, PNG
• Reduce File Size
• Remove metatags
• Sign
• Stamps
• Compare documents
• Insert headers, footers, page numbers
• Merge several PDF files into one single file
• Flatten docs such that images, stamps etc. are flattened
• Print from different apps to PDF

I DO NOT need online collaboration tools, sending for sign etc.

I see various versions such as 9, 10, X Pro, XI Pro, and I am not sure what suits my needs.

What's the most suitable version that I can for my work?

Will this come as a CD or would I have to download the installer?

Season's greetings and thanks in advance!!