Best Course of Action for Removing Large Lipoma Near Spine?

I agree with everything stated by Dr. Rand. It probably SHOULD have been removed earlier before it reached this size. Any skilled surgeon could do it; A Plastic surgeon would probably get you a better scar.
Dr. Placik in Chicago is the biggest contributor to this website and his posts demonstrate a high level of experience and intelligence. I too think you should see him.
Dr. P. Aldea

I would suggest that you have the lipoma excised in the near future. You do not have to be worried about its “proximity to your spine”. A well experienced general or plastic surgeon will do just fine;  the plastic surgeon may pay more attention to the resulting scar.

Best wishes.

It looks large enough to need a direct excision and submit it for pathology for examination.
Because it is lage I would not recommend liposuction to remove this lipoma
Design and placement of the scar is important. I am biased, I would recommend a Plastic Surgeon

There would be no need of the talents of a spinal (neurosurgeon) in this situation. Either a general surgeon or a plastic surgeon would be fine. A plastic surgeon might give you a somewhat better looking scar if this is important to you. The skin over a lipoma of this size has been stretched so much that you are likely to get a half way decent result from either type of surgeon.
If the lipoma is tender you might be hosting an angiolipoma of the type that might infiltrate into the muscle (paravetebral lipomas may do this) so Dr. Rand's advice is sage: an MRI might be of benefit. This is no big deal it just might mean some of the muscle will be sacrificed to allow total extirpation of the mass.
As usual, waiting provides no advantage so I would see a physician sooner rather than later. I agree with Drs. Rand and Aldea, Dr. Placik would be a good choice.

 You might want to get an MRI to be sure it isn't infiltrating the muscle but otherwise, a plastic surgeon would be the best choice for this.  Remove it sooner than later so it doesn't get bigger and become more of an issue.  I would suggest you call Dr. Placik in Chicago!