I don't know if you need more than a straight stitch machine for travel. They are some what limiting if you need to do applique etc....but I would highly recommend a vintage 301 !!! It won't break on you and you know it will be around for another 50 years. You can get one in the $100 range and it will out sew any other "new" machine on the market. If you need some other stitches and not just a straight stitch I've heard good things about the Janome Jem. I have a closet full of vintage machines I take turns bringing to charity events and sew days so I don't have to lug my heavy, and expensive Bernina around.

if just quilting, you cannot beat a singer featherweight ... all my friends and I have them and it's all we use for quilting in classes...self contained, lots of accessories available, not expensive if you hang around ebay for awhile....look for the weeks when they have lots available....the last ones sold will have the cheapest price.... and they are tough and sturdy... (this does NOT refer to new small singers....just the old ones)

I also like these 3/4 size Janome machines. They do a wonderful free motion stitch too.
Else I would opt for a older mechanical Singer $35-45 or other machine still mostly metal from the 1970 or before off Craig's list.
A nice portable vintage machine with a straight stitch only is the Singer 301 ($100 range). I also think that machine would keep its value.

I agree with GrannieAnnie about not buying a new "cheap" Singer. I bought the 7469Q confidence quilter brand new and have had nothing but trouble. I now sew on a Singer 15-91 that I bought at the Salvation Army for $75 dollars and it sews like a dream, heavier than a boat anchor though.

whatever you get make sure you can needle down... I have a small white that has a table.....and you can Free-Motion with it..
White Sewing Machine: Quilt and Sew Compact 1730

this is the one I have and I love it...http://www.sewingmachineoutlet.com/white1730.htm

an inexpensive brother from wally world is a good choice- they are really nice machines- when we had the sewing school we had 5 of them (ranging in price from $79-$139) all of them held up to lots of abuse-use by many different people with different skills and styles---i also have a designer 1 and there were times when people would wait around for one of the brother's instead of sitting down at the viking-
all 3 of my granddaughter's have been using brothers for 6 years now-
i also hate lugging my viking to classes and such- last summer i spent $25 on a vintage singer for lugging around---best $25 i ever spent---but if you want something new-i'd go for a brother. :)

Last Christmas, I got a Janome Magnolia 7330 for the same purpose. I love it and use it almost exclusively--cost around $400

Ditto, sometimes you can get a good old singer on ebay or CL and if you get a 301A the feed dogs drop and you can FMQ with it and it only weighs about 16 lbs.
Or a singer featherweight, about 12 ibs, love them for just straight sitiching.

Posted before I read both pages. So I agree with Candace and Deemail ;)

I'd look on Craigslist for an older machine. I have an older singer that I love!!

I have the Brother machine and love it. Very lightweight and dependable, even comes with the 1/4 inch foot. I bought mine from overstock.com.