I live in the UK, and I want to watch lots of Portuguese and/or
Brazilian TV channels.  In particular, I want RTP 1 and RTP 2 (both
from Portugal), and SIC (from Brazil), but if I can't get these,
others will do!

What is the cheapest/best way to receive them?  Can I get them through
cable, or would I need to get some sort of satellite dish?  And who
provides them?

You can perhaps get RTPi (the i stands for international).  Here's the
contact info, which i found at
http://www.rtp.pt/web/empresa/contactos_empresa.shtm:



Emissões Internacionais
Telf.: (00 351) 217 947 481
E-mail: rtpi@rtp.pt / rtpafrica@rtp.pt

The following programmes from Portugal via satellite are not encrypted
(but before buying a satellite dish you should check the dish size
necessary for your region):
http://www.lyngsat.com/freetv/Portugal.shtml

The many satellite channels from Cabo TV may only be available within
Portugal:
http://www.tvcabo.pt/comum_English.asp
http://www.lyngsat.com/dig/cabo.shtml

If you are interested in receiving Cabo TV here is the footprint of
Hispasat 1C:
http://www.hispasat.com/FlotaSat/pop_up_cobH1C-2.htm

SIC is also broadcast by the French TPS:
http://www.tps.fr/v2/frameset.htm?arg=f_contenu/D/D_G16_vosquestions.htm&menu=z2

The Portuguese version of EuroNews is available in England:
Eurobird 1 satellite (28.2 East) 11681 V (you have to change the
language setting of your satellite receiver:
http://www.lyngsat.com/eb1.shtml
http://www.lyngsat.com/dig/skyuk.shtml

Did you already ask you local cable operator?

Instead of the TPS link in my previous comment:
http://www.tps.fr/v2/f_contenu/B/B_G09_sic.htm

http://www.tps.fr/

SIC is not from brazil.. Sic is a portuguese one. They have SIC
Internacional that broadcasts to a lots of countries including Brazil

Although this question has expired I would like to add that since a
couple of day the Brazilian "Record International" is available in the
UK via Sky Digital.
However, I don't know if this programme will remain an unencrypted
channel or not.
You can find more information here (26/09/03 and 25/09/03):
http://skydigital.mediabullet.co.uk/index.php?page=home

Frequency etc. (11390 H):
http://www.lyngsat.com/dig/skyuk.shtml

Record International:
http://www.recordinternacional.com.br/